My email account is at panix.com (I buy my IP from Cablevision). I Telnet to panix for interaction. This involves the Telnet command and when panix answers I have to type in my name. They then ask for my password. I want to create one command that Telnets, waits for the answer, sends my name, and then waits for a reply, and finally sends my password. And then disappears leaving me connected for further interaction. Back in CP/M-80 days there was a small programlet that you ran and it enabled you to interact with batch files. DOS never had (as far as I know) anything like that. The CP/M thingie was part of Kildahl's original version; not the ZCPR extensions.
Some more constraints - I do not use TC; only TCC. Kermit 95 is a graphical program and not at all what I want. I do have a way of scripting Telnet commands - my Emacs-like editor (Epsilonc) is quite capable of doing that with built-in Telnet. The problem with that is that I want to end up at a command prompt and there is no easy way to scriptedly get out of Epsilon and drop into the command prompt.
IIRC, Kermit95 also had a console mode. Doesn't it go without saying that after you do a telnet login, you're in a terminal emulator of some kind and with a command interpreter, namely the remote shell?
It's not terribly clear what you want to do ... have a telnet session and a local command prompt running in the same console and be able to switch between them? TCC (not TC) can use alternate console screen buffers (see @CONSOLEB) but if telnet were running in one of them, I don't know how you'd get out of telnet.